Aeroplane with rotating wings



June 29 1926.

J. DE LA C!ERVA AEROPLANE WITH ROTATING WINGS Filed Marc.h 31 1923 with rotating win Pathted June 29, 1926.

PATENT OFFICE.

Application illed Iarch 31, 1933, Serial 10.828.217, and in Spain April 1l, 19.

In my former British patent specification No. 165,748, I have described an aeroplane consisting essentially of an ordinziraerop ane provided with all the elements necessary for its progress and steering, such as the motor,propeller, undercarriage, rudder, etc. in which, however, the wings, instead of remaining fixed relatively to it, as in the ordinary aeroplane, revolve freely by virtue of the supporting reaction of the wind during forward movement upon them, around a shaft common to all of them and nessarily inclined backward.

In the accompanying drawings:

Figures 1 and 2 are illustrations of such forms of machines.

Figures 3, 4 and 5 illustrate the present invention.

Figures 1 and 2 illustrate two diflerent types of said known apparatus. The main defect of this known type of aeroplane, when all wings rotate in the same direction, lies in the lateral displacement of the centre of pressure in the assemblage of such rotating wings, due to the want of symmetry in the velocities of the advancing and the retreating wings relatively to the wind, an arrangement which necessitates the use of two groups of wings revolving in opposite directions, as in Figure 1, accompanied by aerodynamic and structural disadvantages, or else the counteraction of such want of. etry by producing a, lift on the opposite side, in which latter arrangement .it is necessary to arrange the wings with a suitable negative inclination with reference to the rotating shaft and to constrct them with wing sections of low serodynamic power. 'The latter condition neces sitates a very accurate calculation and a difiicult and uncertain adjustment, as well as a considerable increase of the wing surface, as in Figure 2, and neither system does away with the structural difliculties inherent in the necessity of naing shaft tubes capable of resisting great bending stresses and consequenfly of at wei ht and diameter, nor with the pro lems of bracing the wings of the requisnte length. The improvement which forrns the subject matter of this invention consiste in arranging the wings on a, rotative 1hember, in such a manner that' eaeh wing can move freely in a plane which contains the axis of rotation (9 pp oximatel so). The burings .required for all the wings are fixed to a common armature or su port such as the said rotative member w ch is itself capable of rotating freel on a radial, axial or hall bearing connecte through its other ring to the body of the aeroplane by means of some structural device, as for instance, a pyramid formed by four tubes. Figure 3 shows such an arrangement -wherein monoplane wings are used -eebeingthe joints of the two symmetricalwings -aa, .r the reinforcing braces of the wings, L the base or support of the win which are mounted by bearings on the axis E su orted on the tube pyramid t. e

eavy shaft Figures 1 and 2, can thus be dispensed with. Similar arrangement would apply to the em loyment of wings for biplanes or multip nes. v

There need be no device'for the change of pitch, nor need the upward swinging movement of the wings be limited. It is preferable however in order to avoid foulmg the propeller or the ground to limit their downward movement by any suitable means such as for example, steel or rubber springs mounted in any convenient manner, for instance by securmg one end to the upper surface of each wing and the other end to an upwardextension of the axis of rotation.

The operation is as ollowsWhen the aeroplane runs over the starting course, the system of wi acquires a mtary-movement due to the action of the wind on the wings or if'it is desired to shorten the run preliminary to taking off, an initial rotatin may be imparted to the wing system by any" suitable means. The speed of rotation generates a centrifugal force F, see Fi re 4,

applied to the centre of gravity ofeac wing C and acting perpendicular to the axis et rotation, whfle the lifting reaction S is directed perpendicularly to the wing, and both forces constantlybalance each other, so that the resu ltant coincides with the straigbt lino which connecte the joint. e of the wing with the point P of application of the lifting reaction, the consequenoo being that, under such conditions, the wing behaves at a given moment asif it were ri%Iy connected' to the axis of rotation. e joint or les below wmg to the of and! aPpar atus, mumh,g t tlflgl9 .-rwhmh ur ymmwally he wing forms with the axis et rotation n1ay he that which is suitablo, that is, approximately a right angle.

Some of the adrantages obtaiued are as follows:

1. The centering of pressure and lift is mechanical, and not aerodynamical, and the system by reason of its jointed construction cannot transmit moments wlnich tend to tip the apparatus over. The aermlyn:unical lateral displacement of the centre of pressure gires rise to a slight inclination only of the means of rotation, sec. Figure 5, and consequently to a small deviation of the. lifting, reaction coinciding thercuith, thereby Causing the apparatus to incline slightly, au effect whicl1 n1ay be neutralized by the twisting moment due to the engine and propeller, but which in any case is et no importance, its extent being reprcsented l y the small angle B (Fig. 5). The ability in use one group of wings al] revolring in the same direction without requiring any rigid stays or any calculations for adjustmcnt, or running any danger of the system ,rctting out of order.

2. Owing to the absence ol lxending n10- ments, the al ility to dispense \\ilh a heavy shaft tube and its support and substituting a simple and light structural dcvice.

3. The alility to use win;r sections 01 the highest efiicienc v without auy negatire inclination and with a reduction of the necessary wing surface resulting theretrom.

4. Absolutely automatic stability, which is not dependent upon the aeroplane maintaining flying speed, as in the case of fixed wing aeroplanes. The aeroplane of the present invention may he said to be supported by the joints of the Wings whieh allow a temporary displacement of the plane of rotation of the. wings relatively to the remainder of the apparatus, when a mlling motion tends to destroy stability. The lift applied to the axis of rotation produces moments opposed t0 a rolling motion.

It is clear that the invention is capable of modifications in the details of construction without altering its essential character.

Having now particularly described and asccrtained the nature of my said invention and in what manner the same is to be performer] I declare tl1at wlmt I daim is:

1. In aircraft, an aerofoil system comprising a plurality of wings mounted to r0- tate freely by virtne of the action of air currents upon thcm, a supporting structure se cured to the body of the aircraft and constitutirig a center of rotation for the system and articulatcd joints between the wings and the supportiug structure such that during rotation of the system each wing is ca pal le 0f assumin g at every moment a position in which the centritugal force produced by rotation and the lift due to the action of the. aircurrcnts tend towards equilibriuln.

2. In aircraft, an aeroioil system comprising a plurality ot' Wings mounted to rotate freely by virtue of the action upon them of air eurrents, a supporting structure secured to the body of the aircraft and constituting a conter ot' rotation for the system-and articulatcd joints between the wings and said supporting structure permitting eaeh wing to swing about an axis that is transverse to the axis of rotation, the joints being located relatively near to the center of rotation and below the aerodynamic plane of each wing. V

3. In aircrait, an aerotoil system comprising a plurality of rotative wings ficxibly jointed to a common supporting center of rotation so as to be capable of revolving freely, under the influence of an airstream, about an axis upwardly directed and so that (:lCll wing is free to swing about an axis that is transverse to the axis et rotation. wliern- 1) at all times during revolution of the syslem each wing may assume positions in which the centrifugal force produced by rotation and the lift due to the action of the airstream tend towards equilibrium.

4. In aircraft, a wing-supportingj structure secured to the body of the aircraft. a bearing mounted on said .supporting structure t0 rotatc trcel y with its axis ot' rotation inclined to the axis of tluusl of the propelling means of the aircraft, a plurality ot' wings synunetrically disposed about the axis of rotation and hinge-jointed to tl'e said bearingr at points closely adjacent theaxis of rotation in such a manner that each wing is free to swing. in a plane, perpendicular to that wherein it is at any instant rotating. the Wing system being adapted to rotate freel v l y virtne only of the action of air currents on the wings.

In testimony whereof I aflix my signature.

JUAN DE LA CIERVA. 

